It is desirable to provide a pushbutton dial for subscriber telephones which operates in conjunction with standard pulse dial central office equipment to provide such central office subscribers with the advantages of pushbutton dialing. Touch tone type dials require special frequency responsive electronic central office equipment.
One dialer which might be adapted for this purpose is described in U.S. Pat. No. 3,760,121. The problem with the dialer described in such patent, however, is that it requires the entire telephone number to be stored before it can begin transmitting dial signals which slows down the dialing procedure excessively.
It is therefore an object of the present invention to provide a simple and relatively inexpensive and improved automatic pushbutton dial system for a subscriber telephone.
Another object of the invention is to provide a pushbutton dial for a dial pulse telephone system which transmits reduced rate dial pulse signals simultaneously with the keying in of telephone numbers.
A further object of the invention is to provide a replacement telephone dial capable of being mounted in any standard telephone set with minimum alteration of the existing physical structure to provide the telephone set with pushbutton dialing capability.